1. Field
This disclosure relates to a method for epitaxial growth, and more particularly, to a method for epitaxial growth, wherein a quantum dot is formed on an epitaxial layer using a quantum-dot forming material with an excellent lattice matching property, and the formed quantum dot is positioned on a defect in the epitaxial layer, thereby minimizing transfer of the defect into an epitaxial layer formed through a subsequent process.
2. Description of the Related Art
In formation of quantum dots on a substrate or epitaxial layer, when a quantum-dot forming material has a lattice constant similar to that of the epitaxial layer, i.e., when the quantum-dot forming material and the epitaxial layer are lattice-matched with respect to each other, the quantum dots are not formed well. To solve such a problem, there has been reported a method in which a surface treatment is performed by coating an anti-surfactant on an epitaxial layer, and quantum dots are grown on the epitaxial layer using a group III nitride-based material with an excellent lattice matching property through a vapor phase epitaxial process [Appl. Phys. Lett 69 (1996) pp. 4096].
As a method of forming quantum dots using such an anti-surfactant, Japanese Laid-open Patent Publication No. 1999-354843 proposes a technique which forms a crystal layer grown while burying quantum dots but suppressing unintended quantum dots. In addition, Japanese Registered Patent Publication No. 3660801 proposes a technique for a GaN-based semiconductor light emitting device using quantum dots, and Japanese Registered Patent Publication No. 3667995 proposes a technique for a method of fabricating quantum dots and their use. In the three techniques, a high-efficiency light emitting device can be obtained by optimizing the size of quantum dots and their entire distribution.
As described above, in related art techniques, production of unintended quantum dots is suppressed, or optical characteristics of quantum dots are applied to a light emitting device. However, the quantum dots may induce lattice defects due to the difference of lattice constants between the quantum dots and a thin film formed in a subsequent process.